Answer:A and B
Explanation:
A substance is said to be polar when it is having a dipole (a delocalised positive and negative charge) or it is ionic (dissociate into ions when dissolved in water)
You have two compounds that you have spotted on a TLC plate. One compound is more polar than the other. You run the TLC plate with neat hexanes and find that only one spot moved a small distance up the plate. Next you made a 50/50 mixture of hexanes and ethyl acetate. What might you expect to see on your TLC plate (what would the spots do)?
Answer:
The two spots will move up the plate.
Explanation:
We have to first understand the rudiments of chromatography. In chromatography, there is a stationary phase and a mobile phase. The stationary phase does not move. In this case, the stationary phase is the TLC plate.
The mobile phase is the solvent used to perform the chromatography. The movement of the spots depends on the composition of the solvent.
When neat hexane was used, only one spot was moved. This must be due to the interaction of the nonpolar hexane with the less polar compound. However, when a 50/50 mixture of hexanes and ethyl acetate is used, the both compounds are found to move up the plate.
A sample of polystyrene, which has a specific heat capacity of 1.880 J.g .°C , is put into a calorimeter (see sketch at right) that contains 300.0 g of water. The polystyrene sample starts off at 94.9 °C and the temperature of the water starts off at 22.0 When the temperature of the water stops changing it's 27.7 °C. The pressure remains constant at 1 atm. Calculate the mass of the polystyrene sample.
Answer:
56.6g
Explanation:
Given that :
Mass of water, m1= 300.0 g
Temperature of water, T1= 22°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of polystyrene, m2=?
Temperature of polystyrene = 94.9
Specific heat capacity of polystyrene, c2= 1.88 J/g°C
Final temperature = 27.7 oC
Heat lost by polystyrene = Heat gained by water
mc(dT) = mc(dT)
m2 * 1.88 * (94.9 - 27.7) = 300 * 4.184 * (27.7 - 22)
m2 * 1.88*67.2 = 300*4.184*5.7
126.336 * m2 = 7154.64
m2 = 7154.64 / 126.336
m2 = 56.631838
Hence, mass of polystyrene = 56.6g
Convert 392 K into Celsius.
Your answer should have three significant figures (round your answer to the nearest whole number).
Use −273∘C for absolute zero.
Answer:
118.85 degrees celsius (not sure if it is)
Answer:
118 is correct
Explanation:
:)
Which unit is used for measuring atomic mass?
А.atomic mole
B. grams/mole
C. grams
D. atomic mass unit
E. atomic mass weight
Am I right????????????????Btw question was “Name four abiotic factors shown in the above prairie ecosystem?
Convert 75g of NaOH to moles
Answer:
75g and I no inglish I my espanish perfec
Explanation:
PLEASE HELP
MY PARENTS WILL KILL ME IF I DONT GET MY SCHOOL WORK DONE BY 12 PM TODAY!! AND I DONT UNDERSTAND IT!!
If the mass of an unknown object is 2 grams and the volume is 2.35 cubic centimeters, what is the density of that object?
a. _________________________
b. Look back at Table 4.1. Based on your calculated density, what is the substance? _________________________
Answer:
oh ok
Explanation:
26. Find the volume of 111.6 grams of NH3 gas.
Answer:
It is 148.82 L
Explanation:
I need more points. And I hope this helps.
how to rapidly separate red#40 from ZnO
Answer:
your question :how to rapidly separate red#40 from ZnO
answer :Red #40 is soluble in water while zinc oxide is not. 4- heat the solution of red #40 and water until water evaporates and red#40 remains
hope it's help
#carryONlearning(feso4.(Nh4) So4. 6H2o) +Kmno4+H2So4_Fe2(So4)3+K2So4+mnSo4+(Nh4)2So4+H2o
Answer:
balancing the equation?
a)
Name the following compounds
CH, -CH-CH
(i)
CH, Br
-
Answer:
methyl, ethyl,
Explanation:
that should be the case
A 51.1g sample of brass is put into a calorimeter (see sketch at right) that contains 250.0g of water. The brass sample starts off at 95.4°C and the temperature of the water starts off at 25.0°C. When the temperature of the water stops changing it's 26.4°C. The pressure remains constant at 1atm.
Required:
Calculate the specific heat capacity of brass according to this experiment.
Answer:
0.415 j/g°C
Explanation:
Given that :
Mass of water, m1= 250.0 g
Temperature of water, T1= 25°C
Specific heat capacity of water, C= 4.184 J/g°C
Mass of brass , m2= 51.1g
Temperature of brass = 95.4°C
Specific heat capacity of brass , c2=?
Final temperature = 26.4°C
Heat lost by brass = Heat gained by water
mc(dT) = mc(dT)
51.1 * c * (95.4 - 26.4) = 250 * 4.184 * (26.4 - 25)
51.1 * 69 * c = 250 * 4.184 * 1.4
3525.9c = 1464.4
c = 1464.4 / 3525.9
c = 0.4153265
c = 0.415 j/g°C
Specific heat capacity of Brass for the experiment = 0.415 j/g°C
4 moles of monoatomic ideal gas is compressed adiabatically causing the temperature to increase from 300 K to 400 K. Calculate the work done on the gas in units of Joules (if the answer is negative, be sure to enter a negative sign in your answer).
Answer:
the work done on the gas is 4,988.7 J.
Explanation:
Given;
number of moles of the monoatomic gas, n = 4 moles
initial temperature of the gas, T₁ = 300 K
final temperature of the gas, T₂ = 400 K
The work done on the gas is calculated as;
[tex]W = \Delta U = nC_v(T_2 -T_1)[/tex]
For monoatomic ideal gas: [tex]C_v = \frac{3}{2} R[/tex]
[tex]W = \frac{3}{2} R \times n(T_2-T_1)[/tex]
Where;
R is ideal gas constant = 8.3145 J/K.mol
[tex]W = \frac{3}{2} R \times n(T_2-T_1) \\\\W = \frac{3}{2} (8.3145) \times 4(400-300) \\\\W = \frac{3}{2} (8.3145) \times 4(100)\\\\W = 4,988.7 \ J[/tex]
Therefore, the work done on the gas is 4,988.7 J.
A) Calculate the vapor pressure of a 7% by mass benzaoic acid in ethanol solution at 30°C. The vapor pressure of pure ethanol at this temperature is 13.40 kPa. ( assume a 100 g of solution)
B) Calculate the boiling point of the solution above
Answer:
the answer is C
Explanation:
Household hydrogen peroxide is an aqueous solution of hydrogen peroxide (H2O2), and its concentration is often measured as a percent by weight. Most drug stores sell 3% solution, which means there are 3.0 g of H2O2 per every 100 g total of solution (H2O2 H2O). For the kinetics experiment, 15 mL of 3% (w/w) hydrogen peroxide solution was poured into a measuring cup with 120 mL of water. 5 mL of 1M sodium carbonate solution (Na2CO3) was also added to the mixture. What is the molar concentration (molarity) of hydrogen peroxide (in mol/L) of the final solution
Answer:
0.093 M
Explanation:
First, we assume that the density of household hydrogen peroxide is 1 g/mL. We also assume that there's no reaction between hydrogen peroxide and sodium carbonate, if there were, in the end all hydrogen peroxide would be consumed.
Now we calculate how many grams of H₂O₂ were added, using the given volume, concentration and density:
15 mL * [tex]\frac{1gSolution}{1mL}*\frac{3gH_2O_2}{100gSolution}[/tex] = 0.45 g H₂O₂We convert grams to moles:
0.45 g H₂O₂ ÷ 34 g/mol = 0.013 mol H₂O₂
Now we divide the number of moles by the final volume, to calculate the molarity of H₂O₂:
Final Volume = 15 mL + 120 mL + 5 mL = 140 mL140 mL / 1000 = 0.140 LMolarity = 0.013 mol H₂O₂ / 0.140 L = 0.093 MBased on the given concentration of the original hydrogen peroxide solution, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
What is the concentration of the hydrogen peroxide solution?Assuming that the density of household hydrogen peroxide is 1 g/mL and that no reaction occurs between hydrogen peroxide and sodium carbonate.
The mass in grams of H₂O₂ added is first determined using the given volume, concentration and density:
mass = volume * density * concentrationmass = 15 mL * 1 g/mL * 3g/100g = 0.45 g H₂O₂
Moles of H₂O₂ is determined as follows:
moles = mass /molar massmolar mass of H₂O₂ = 34 g/mol
moles of H₂O₂ = 0.45 g H₂O₂ / 34 g/mol
moles of H₂O₂ = 0.013 mol H₂O₂
molarity of H₂O₂ is then calculated as follows:
molarity = moles/volume in Lfinal volume = 15 mL + 120 mL + 5 mL = 140 mL
final volume = 140 mL / 1000 = 0.140 L
molarity = 0.013 mol H₂O₂ / 0.140 L
molarity of H₂O₂ = 0.093 M
Therefore, the molarity of the hydrogen peroxide (in mol/L) of the final solution is 0.093 M.
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i don’t understand this please help!!!
Answer:
Numbers after atoms are subscripts. Numbers before atoms are coefficients.
Equation: 2Na +Cl2 -> 2NaCl
Given: 6.8 grams of Na
Unknown: moles of NaCl
Set up: [tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Explanation:
We know that the reactants are Na and Cl and that what is being produced, the products, is NaCl.
Na + Cl -> NaCl
CAREFUL! Cl is a diatomic ion, is it gets a subscript of 2! This means there need to be 2 cl atoms on the right side as well. But now there are 2 Na on the right side. So we multiply Na by 2 on the left so that both sides have two Na atoms.
2Na +Cl2 -> 2NaCl
B)
We know that there are 6.8 grams of Na. This is our given.
What do we want to find out? We want to find how many moles of NaCl there are, so that is our unknown.
C) A mole ratio is exactly what it sounds like. From our balanced equation, we can see that there are 2 moles of Na and 2 moles of NaCl. In other words, there are 2 moles of Na for every 2 moles Nacl. In notation, this is [tex]\frac{2 mole Na}{2 Mole NaCl}[/tex] or 2:2. You can simplify to 1:1 ratio, but as equations get more complex I find it easier to not. It depends on what your teacher wants and what you find easier.
D)
By set up I assume they mean stoichiometry (chemistry conversion) . First I'm going to split up the set up so that it is easier to understand.
We start with the given and convert that into moles Na. We can do this by remembering that there are 22.99 grams for every 1 mole Na:
6.8 g Na* [tex]\frac{1 mole Na}{22.99g Na} = .2957 moles Na[/tex]
Now we can use that mole ration we found in part C to convert moles of Na into moles of NaCl:
[tex].2957 moles Na *\frac{2 moles NaCl}{2 moles Na}= .2957[/tex]
Usually, we will put these together to get
[tex]6.8g Na *\frac{1 mole Na}{22.99 g Na}*\frac{2 moles NaCl}{2 moles Na} =.2957 moles NaCl[/tex]
Tip: in Stoichiometry, it is important to remember that your units should cancel out until you only have the units you want. If there are moles of Na in the numerator, there should be moles of Na in the denominator of the following fraction. If there are grams Na in the numerator, there should be grams Na in the denominator and so and so on until you are only left with the unit you want, which, in this case, is moles of NaCl.
According to the following reaction, how many grams of carbon tetrachloride will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide? carbon disulfide (s) + chlorine (g) carbon tetrachloride (l) + sulfur dichloride (s) grams carbon tetrachloride
Answer: 15.0 g of [tex]CCl_4[/tex] will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide
Explanation:
To calculate the moles :
[tex]\text{Moles of solute}=\frac{\text{given mass}}{\text{Molar Mass}}[/tex]
[tex]\text{Moles of} Cl_2=\frac{27.7g}{71g/mol}=0.390moles[/tex]
The balanced chemical reaction is:
[tex]CS_2(g)+4Cl_2(g)\rightarrow CCl_4(l)+2SCl_2(s)[/tex]
[tex]Cl_2[/tex] is the limiting reagent as it limits the formation of product and [tex]CS_2[/tex] is the excess reagent.
According to stoichiometry :
4 moles of [tex]Cl_2[/tex] give= 1 mole of [tex]CCl_4[/tex]
Thus 0.390 moles of will give = [tex]\frac{1}{4}\times 0.390=0.0975moles[/tex] of [tex]CCl_4[/tex]
Mass of [tex]CCl_4=moles\times {\text {Molar mass}}=0.0975\times 154=15.0g[/tex]
Thus 15.0 g of [tex]CCl_4[/tex] will be formed upon the complete reaction of 27.7 grams of chlorine gas with excess carbon disulfide
All of the following are physical changes except
A. ice melting.
B. plaster hardening.
C. paint drying.
D. rocket fuel burning.
Answer:
rocket fuel burning i think
How does a temperature increase cause the rate of a reaction to increase?
A. It increases the kinetic energy of the molecules.
B. It decreases orientation requirements of the molecules.
C. It increases the equilibrium constant for the reaction.
D. It decreases the activation energy of the reaction.
Answer:
B
Explanation:
"The temperature increases cause the rate of a reaction to increases the kinetic energy"
What is rate of reaction?
The reaction rate, also known as the rate of reaction, is the rate for which a chemical reaction occurs, and is proportional to increase in product concentration per unit time and the reduction in reactant concentration per unit time. The rate of reaction varies greatly.
What is kinetic energy?
An object's kinetic energy is the energy it has as a result of its motion. It is the amount of work required to push a body of a given mass from rest to a certain velocity. The body keeps its kinetic energy gained during acceleration unless that speed changes.
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1. 1 N2+ 3 H2→2 NH3
c.How many moles of nitrogen are needed to produce 12 moles of nitrogen trihydride?
[tex]\displaystyle 6 \ mol \ N_2[/tex]
General Formulas and Concepts:Math
Pre-Algebra
Order of Operations: BPEMDAS
BracketsParenthesisExponentsMultiplicationDivisionAdditionSubtractionLeft to RightChemistry
Atomic Structure
Writing CompoundsStoichiometry
Using Dimensional AnalysisReactions RxNExplanation:Step 1: Define
[RxN - Balanced] N₂ + 3H₂ → 2NH₃
[Given] 12 mol NH₃
[Solve] x mol N₂
Step 2: Identify Conversions
[RxN] 1 mol N₂ → 2 mol NH₃
Step 3: Stoich
[DA] Set up: [tex]\displaystyle 12 \ mol \ NH_3(\frac{1 \ mol \ N_2}{2 \ mol \ NH_3})[/tex][DA] Multiply/Divide [Cancel out units]: [tex]\displaystyle 6 \ mol \ N_2[/tex]Answer:
[tex]\boxed {\boxed {\sf 6 \ moles \ of \ N_2}}[/tex]
Explanation:
1. Balance Equation
We are given the reaction:
[tex]1 N_2+3H_2 \rightarrow 2 NH_3[/tex]
The equation is already balanced. Both sides have 2 moles of nitrogen and 6 moles of hydrogen.
2. Conversions
In this reaction, 1 mole of nitrogen produces 2 moles of nitrogen tryhdride:
[tex]1 \ mol \ N_2 \rightarrow 2 \ mol \ NH_3[/tex]
3. Stoichiometry Calculations
Use the conversion rate as a fraction.
[tex]\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
Multiply the number of moles of nitrogen trihydride produced: 12 moles.
[tex]12 \ mol \ NH_3 *\frac{ 1 \ mol \ N_2}{2 \ mol \ NH_3}[/tex]
The moles of nitrogen trihydride cancel.
[tex]12 *\frac{ 1 \ mol \ N_2}{2} = \frac{ 12 \ mol \ N_2}{2}[/tex]
[tex]6 \ mol \ N_2[/tex]
6 moles of nitrogen are needed to produce 12 moles of nitrogen trihydride.
What do scientists use to answer scientific questions?
A. A scientific guidebook
B. The scientific method
C. A scientific law
D. The atomic theory
Scientists uses scientific methods and well designed experiments to solve a scientific question. They can use some laws and previous scientific records as an aid.
What is a scientific question ?A scientific question arises from selected topic under study. A scientific question addresses a natural phenomenon, a socially relevant problem or a any personal curiosity.
The scientific question must be testable. The first prediction for the question based on observation and scientific records is called the hypothesis.
The hypothesis must be tested using a well designed scientific experiment based on a scientific method. The methodology should be clearly specify what to collect and how to use them. Hence, option B is correct.
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A: A 21.3−g sample of dinitrogen monoxide is confined in a 5.76−L vessel. What is the pressure (in atm) at 111°C?
B: Find the density of Freon−11 (CFCl3) at 157°C and 4.65 atm.
g/L = ?
Answer:
A. 2.65 atm.
B. 18.11 g/L.
Explanation:
A. Determination of the pressure
Mass of N₂O = 21.3 g
Volume = 5.76 L
Temperature (T) = 111 °C
Pressure (P) =.?
First, we shall determine the number of mole in 21.3 g of dinitrogen monoxide, N₂O. This can be obtained as follow:
Mass of N₂O = 21.3 g
Molar mass of N₂O = (14×2) + 16
= 28 + 16
= 44 g/mol
Mole of N₂O =?
Mole = mass /Molar mass
Mole of N₂O = 21.3/44
Mole of N₂O = 0.484 mole
Next, we shall convert 111°C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Temperature (T) = 111 °C
Temperature (T) = 111 °C + 273
Temperature (T) = 384 K
Finally, we shall determine the pressure. This can be obtained as follow:
Number mole of N₂O = 0.484 mole
Volume = 5.76 L
Temperature (T) = 384 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =.?
PV = nRT
P × 5.76 = 0.484 × 0.0821 × 384
Divide both side by 5.76
P = (0.484 × 0.0821 × 384) / 5.76
P = 2.65 atm
B. Determination of the density of CFCl₃
Temperature (T) = 157°C
Pressure (P) = 4.65 atm.
Density of CFCl₃ =?
First, we shall determine the molar mass of CFCl₃. This can be obtained as follow:
Molar mass of CFCl₃ = 12 + 19 + (35.5×3)
= 12 + 19 + 106.5
= 137.5 g/mol
Next, we shall convert 157°C to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Temperature (T) = 157 °C
Temperature (T) = 157 °C + 273
Temperature (T) = 430 K
Finally, we shall determine the density of CFCl₃. This can be obtained as follow:
Temperature (T) = 430 K
Pressure (P) = 4.65 atm.
Molar mass of CFCl₃ (M) = 137.5 g/mol
Gas constant (R) = 0.0821 atm.L/Kmol
Density (D) of CFCl₃ =?
D = PM / RT
D = (4.65 × 137.5) / (0.0821 × 430)
D = 18.11 g/L
Estimate how much heat in joules is released when 25.0 g of water (C = 4.184 J/g°C) is cooled from 80.0°C to 30.0°C?
Answer:
5230 J
Explanation:
m = 25 g = 0,025 kg
c = 4,184 J /(g * °C) = 4184 J /(kg * °C)
[tex]t_{1}[/tex] = 80 °C
[tex]t_{2}[/tex] = 30 °C
The formula is Q = c *m * ([tex]t_{2} - t_{1}[/tex])
Calculating:
Q = 4184 * 0,025 * (30 - 80) = 5230 J
Note that we get a negative heat (-5230 J). It just means that it is released.
The amount of heat will be 5230 j.
What is heat?
Heat is a type of energy that is transferred between both the system and its surroundings as a result of temperature variations.
Calculation of heat.
Given data:
Mass = 25.0 g = 0.025 kg
C = 4.184 J/g°C
[tex]T_{1}[/tex] = 80.0°C
[tex]T_{2}[/tex] = 30.0°C
Q= ?
By using the formula of heat.
Q = MC ([tex]T_{2} - T_{1}[/tex])
Put the value of given data in heat equation.
Q(heat) = 0.025 × 4.184 ( 30 - 80)
Q(heat) = 5230 J.
Therefore, the amount of heat will be 5230 J.
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GIVING BRAINLIEST AND 20 POINTS
Which number represents precipitation on the hydrologic cycle diagram?
1
2
3
4
Answer:
Number three, because precipitation is rain, which comes from cumulonimbus clouds. Precipitation happens when clouds have accumulated enough evaporated water for the cloud to get heavy and need to get rid of some of the water, which it does through condensing the water and then delivering it as rain.
Hope this helps! Have a wonderful day! (Please give me brainliest and thank you!)
:)
Lesson Question: What is the effect of
pressure on the volume of a gas?
To answer this question, you used weight to
change the pressure of the gas and
measured the
resulting changes to the gas's volume.
COMPLETE
The amount of gas (in terms of moles, mass, and
molecules):
Answer:
pressure
volume
was constant
Boyle's
Explanation:
Answer:
the first one is pressure &volume the second one is was constant the third one is Boyle's
Explanation:
Pleaseee I need help and it is urgent
Answer:
1)4180j
2)15000kj
Explanation:
[tex]1) E=100*(30-20)*4.18=4180j\\2)Q=.5*30*1000=15000kj[/tex]
In the following reduction of iron ore, 3C + 2Fe2O3 –> 4Fe + 3C02, iron is reduced and _____ is oxidized.
A) carbon dioxide
B) carbon
C) iron oxide
D) oxygen
Answer:
B carbon
Explanation:
guessed
WILL GIVE 10 PTS AND BRAINIEST FOR THE RIGHT ANSWER PLEASE HELP!!!
____ is important for making amino acids, proteins, and the chlorophyll a plant uses to carry out photosynthesis.
A. Boron
B. Nitrogen
C. Potassium
D. Phosphorus
E. Calcium
Answer:
c
Explanation:
What mass of KNO, will dissolve in 100 g of water at 100°C?
Answer:
About 170-180 grams of potassium nitrate are completely dissolved in 100 g.
Explanation:
Hello!
In this case, according to the reported solubility data for potassium nitrate at different temperatures on the attached picture, it is possible to bear out that about 170-180 grams of potassium nitrate are completely dissolved in 100 g; considering that the solubility is the maximum amount of a solute that can be dissolved in a solvent, in this case water.
Best regards!
importance of distillation column in industry
Answer:
Distillation columns are used to separate mixed feed streams into their own distinct products.
Explanation:
The primary function of the distillation column is to separate the feed stream into (at least) one highest level product stream and one bottom product stream. The performance of the column separation can be justified by the purity of the upper and lower product streams.